Sexually Transmitted Infections Flashcards
What is the bacteria responsible for causing syphilis?
treponema pallidum pallidum
- there is 11 m new cases a year worldwide
What is the most common age group to have syphilis in canada and what is the gender?
- makes aged 30-39
What is the incubation period if treponema palladium pallidum
1-90 days
What makes up the primary phase of syphilis?
- chancres/skin lesions at the site of inoculation
- usually painless and heals spontaneously
- highly infectious
What is the secondary phase of syphilis?
- signs of the disseminated disease
- occurs 2-12 weeks after th infection
- skin lesions are on the trunk, palms and soles of the feet
- lesion fluid is highly infectious
- signs of other organ involvement
- 3-12 weeks, disappearance of symptoms
- latent phase follows (asymptomatic, antibodies present, untreated patients have 3 outcomes - relapse, no relapse or the tertiary phase)
What is considered tertiary syphilis?
- can occur after initial infection
- neurologic and cardiovascular symptoms
- may have gummas (nonspecific, granulomatous lesions)
Congenital syphilis passed on to the child will give the baby signs of _____ at birth
secondary syphilis
Congenital syphilis can be prevented is woman are treated with ____ early in pregnancy
penicillin
Lab diagnosis depends solely on microscopy and serology for what reasons?
- because treponema cannot be grown in vitro
What two types of microscopy are used to see treponema bacteria?
- dark field or fluorescent microscopy
What are the nonspecific serodiagnostic tests for treponema using nontreponemal antibodies?
- venereal disease research laboratory test
- rapid plasma reagin test
What are the specific tests for syphilis using treponemal antibodies?
- FTA-ABS: florescent treponemal antibody absorption
- agglutination tests ( microhemagglutination test and Treponema palladium particle agglutination test)
What aret eh 2 antibiotics that are used to treat syphilis?
- penicillin and doxycycline
What bacteria causes gonorrhoea? Describe it
Neisseria gonorrhoeae
- gram negative diplococci
Where does gonorrhoea typically infect in the female reproductive tract?
- typically the cervix, the uterus and the fallopian tubes
- also the urethra (in both males and females)
Females have a __ % chance of infection post single encounter, while males have a __ % chance of infection post single encounter
50%
20%
How is gonorrhoea vertically transferred?
- can cause opthalmia neonatorum when passed on to children
N. gonorrhoeae is a ____ that thrives in a humid atmosphere
capnophile
What are the different virulence factors that N. gonorrhoeae possesses?
- Pilus: aids in attachment to human mucosal epithelium - contains constant and hyper variable regions- analagous to immunoglobulins
- Por proteins: forms pores through the outer membrane - antigenic
- Opa proteins: assist binding to the epithelial cells
- LOS: lipooligosaccharide (endotoxin activity)
- RMP proteins: inhibit ‘cidal’ activity of serum
- IgA protease: core contains enzyme- released by cell to destroy IgA
- Capsule: resists phagocytosis- unless antibody is present
Gonorrhoea in females is often asymptomatic, but if symptoms are present they develop in 2-7 days and the main symptom is often _______
vaginal discharge
What are the main untreated complications of untreated gonorrhoea in females?
- PID
- chronic pelvic pain
- infertility
In makes, what is the main symptoms of gonorrhoea?
- urethral discharge
- painful urination
What are the other conditions that are also known to be signs and symptoms of gonorrhoea?
- anorectal (purulent discharge), pharyngeal (sore throat), and ophthalmic infections
- ophthalmia neonatorum in newborns
What is the most useful method of determining a gonorrhoea infection?
- in men- by using a direct gram stain
- uses urethral discharge from symptomatic males with urethritis - gram negative diplococci inside PMNs, diagnostic
- this is not as useful in women - normal vaginal and rectal flora have G- coccobacilli so therefore the bacteria has to be confirmed by culturing
What is the highest amount of STIs reported in canada?
- chlamydia
Chlamydia is considered an ____ ______ bacterium
obligate intracellular
Serotypes A-C of the Chlamydia trachomatis cause what disorder?
trachoma (an infection of the eye)
Serotypes D-K are the cause of ________ and associated ocular and respiratory infections
genital infections
Serotypes L1, L2, L3 cause the systemic disease of _________
lymphogranuloma venerum
What is the life cycle of chlamydia infections?
- elemental body attaches to a specific receptor on the host columnar epithelial cells
- enters the epithelial cells
- forms reticulate/initial body (adapted for intracellular replication)
- replicates by binary fission pf reticulate bodies
- differentiation back into epithelial bodies
- release of epithelial body progeny spreads to adjacent cells (infectious)
Chlamydia is a _______ diagnosis, where they have a clinical suspicion based on symptoms that the patient is experiencing
presumptive
*** however, can also use a positive non culture result, where they use EIA, DFA or nucleic acid detection
What is the gold standard definitive diagnosis of chlamydia?
- culture and ID of inclusion bodies
- combination of 2 non culture methods
What is the major cause of vaginal candidiasis?
- C. albicans
What are the main symptoms of a candidal infection?
- itching
- erythema
- discharge
Trichomoniasis is a protozoan infection caused by what?
- trichomonas vaginalis
What are the clinical signs of a trichomoniasis infection?
- profuse, offensive and hello-green discharge
- can also be asymptomatic
What is the treatment of a trichomoniasis infection?
- metronidazole
HSV-1 infection is primarily where?
- transmitted by the saliva
- oropharyngeal infections in children - cause cold cores after reactivation
HSV-2 infections are a result of what?
- emerged as a result of independent TM via the venereal route
Genital herpes is characterized by what? How long do these show up post infection?
- characterized by ulcerating vesicles
- primary lesion appear on the penis/vulva 3-7 days post infection
What are other symptoms that can be associated with genital herpes?
- swollen lymph nodes, fever, headache, malaise
Healing of genital herpes takes _____
2 weeks
Describe the process of the viral infection going latent, as well as the process of the virus being reactivated
- Latent: the virus gets in through a lesion, goes into the sensory nerve ending and the latent infection travels in the dorsal root ganglion neurons
- Reactivation: travel down the same route- recurrent lesions occur and turn into genital cold cores
A mother giving birth to an infant while having genital herpes leads to _____
neonatal disseminated herpes or encephalitis
How is genital herpes diagnosed?
- virus DNA in vesicle fluid or ulcer swabs
- immunofluorescence
What is the treatment for genital herpes?
- antivirals
- recurrent infections (troublesome - 6-12 months of low dose antiviral to stop/reduce the frequency of recurrences)
Can HPV be grown in a culture?
no
What is required to determine the presence of HPV?
- cytology secretions (pap smears, koilocytes)
- nucleic acid detection via PCR
HPV is a ____ vaccine, with types 6, 11, 16 ad 18
quadrivalent
Why is HIV considered a retrovirus?
because it is a single stranded RNA virus that contains a pol gene that codes for reverse transcriptase
HIV is also a slow, or ____, virus
lentivirus
HIV-1 is separated into 3 groups. What are they?
- M (main) -> A to J
B most common in NA and Europe, while A and C are most common in Africa - N (new)
- O (outlier)
both of these are most common in west central africa
HIV infected cells with a ___ surface marker
CD4
Th cells, for example
What allows the entry of the HIV virus into the cell?
- binding of the viral p120 envelope glycoprotein to a CD4 receptor
The chemokine co-receptor ____ establishes infection, individuals with this gene have deletions that are resistant
CCR5
Disease progression in HIV variants are using the ____ receptor
CXCR4
Viral replication of HIV halts after the integration of the _____, leaving it lying latent in the cell
provirus
HIV transmission is associated with breastfeeding for up to ____
24 months
What is the mainstay of treating an HIV infection?
HAART (highly active antiretroviral therapy)
- combines 2 NRTIs, as well as an NNRTI and a PI drug - seen to have a dramatic effect on the progression of AIDS
What are the drawbacks of HAART?
- mitochondrial toxicity and altered fat distribution
- HIV inhabits CSF and GU tract- unfortunately the drug cannot reach in here- there is a high load in the semen
- can lead to resistance
